This morning while the car was warming up, I decided that I would top off the oil because I knew it was about 1/4 of a quart low. I like to keep my vehicles at the MAX level. I took off the oil cap and started to pour in some oil just to find myself getting showered in oil. There was so much air that it sprayed the oil back at me. I place my hand over the oil fill hole and it feels like there is a fan installed under the valve cover. Is it normal to have air pressure flowing from oil fill while its running? I have never experienced this before. The engine is the 2 AZ-FE (4 cylinder) toyota in a 2008 Scion XB. There is no check engine light on.
Air pressure from the oil fill hole?
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That pressure is from blowby of the ring pack into the crankcase. If the pcv system is up to snuff, there should be a negative pressure(suction) via the filler hole and not pressure/wind as you describe. If it's not merely splashing oil thats usually a early sign of a tired engine. Your's is to new so likely it is engineered to have no flow in the pcv at idle. It is new but may want to check pcv valve anyway.
It sounds like a tremendous amount of blow-by, indicating a serious problem with the engine. Car should be taken to the dealer and repaired under warranty.
I seriously doubt there is a serious problem with that engine! I never open up the cap when the vehicle is running so I can't say this has ever happened to me with my xB.
Originally Posted By: drivewaytech
I place my hand over the oil fill hole and it feels like there is a fan installed under the valve cover. Is it normal to have air pressure flowing from oil fill while its running?
Yes, I think it is. Every single car I've had the occasion to remove the oil fill cap with the engine running has had some air coming out of the oil fill.
Consider that the pistons displace air in the crankcase as well..and it may well be that with the oil fill off, that air gets displaced out of the crankcase. Of course that would mean that air gets sucked back into the crankcase through the oil fill as well, which would explain why the air isn't a constant flow but rather a pulsing one.
I place my hand over the oil fill hole and it feels like there is a fan installed under the valve cover. Is it normal to have air pressure flowing from oil fill while its running?
Yes, I think it is. Every single car I've had the occasion to remove the oil fill cap with the engine running has had some air coming out of the oil fill.
Consider that the pistons displace air in the crankcase as well..and it may well be that with the oil fill off, that air gets displaced out of the crankcase. Of course that would mean that air gets sucked back into the crankcase through the oil fill as well, which would explain why the air isn't a constant flow but rather a pulsing one.
I thought of a tired ring pack to on my subaru as I have the same air coming out of my oil fill cap. This was on the driver's side where I had one clyinder come up 11% low on a compression test (not loosing coolant). However have the same rush of air on the passenger side where both cylinders are at 185psi..
PCV system is working too.
PCV system is working too.
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There is only 15k miles on the motor. I do not make a habit of taking the oil cap off while the engine is running, but have done it several times to look at top end oil flow or remembered to add some oil after I started the engine. I just have never experienced this before. I wish I knew someone with a 2nd gen Scion or 4 cyl. Camry that could check if theirs does the same thing before I drive all the way out to the dealership to have it checked. Again, there is no CEL on and the engine is running just fine. I will have to hunt down the PCV and check it. This is the first 2AZ-FE engine I have ever dealt with.
Nothing wrong with that engine.
Next time add oil when the engine is not running.
Next time add oil when the engine is not running.
There is nothing wrong with your engine, that's normal. No need to go back to the dealer about this.
Most people learn quickly that you don't add oil to a running engine.
Most people learn quickly that you don't add oil to a running engine.
I have a 2azfe in a Highlander, and I started the engine to back it off the ramps after an oil change without the cap on since I figured I'd need to add to full and couldn't check on the ramps. I'm not sure if the air was all coming out, or in and out, but there was a good flow of air going somewhere. I certainly wouldn't have tried to pour oil through the hole with it running.
So whatever it is, it's probably normal. Is it good? I don't know. Probably not a big deal, as I don't see camrys, rav 4's and scions littering the side of the road. FWIW, it smelled like air, not blowby.
So whatever it is, it's probably normal. Is it good? I don't know. Probably not a big deal, as I don't see camrys, rav 4's and scions littering the side of the road. FWIW, it smelled like air, not blowby.
Originally Posted By: Buffman
I thought of a tired ring pack to on my subaru as I have the same air coming out of my oil fill cap. This was on the driver's side where I had one clyinder come up 11% low on a compression test (not loosing coolant). However have the same rush of air on the passenger side where both cylinders are at 185psi..
PCV system is working too.
The spaces under your two valve covers are both connected to the common crankcase, so it is not surprising that the rush of air is the same on both sides.
I thought of a tired ring pack to on my subaru as I have the same air coming out of my oil fill cap. This was on the driver's side where I had one clyinder come up 11% low on a compression test (not loosing coolant). However have the same rush of air on the passenger side where both cylinders are at 185psi..
PCV system is working too.
The spaces under your two valve covers are both connected to the common crankcase, so it is not surprising that the rush of air is the same on both sides.
Originally Posted By: LT4 Vette
Nothing wrong with that engine.
Next time add oil when the engine is not running.
Well from this point forward, I will no longer add oil to this engine while it is running unless I am in the mood to be bathed in new motor oil. You have to admit, it would be a fun joke to play on someone. My apologies for sounding like an idiot, but I just have never seen an engine produce that much air through the crankcase.
Nothing wrong with that engine.
Next time add oil when the engine is not running.
Well from this point forward, I will no longer add oil to this engine while it is running unless I am in the mood to be bathed in new motor oil. You have to admit, it would be a fun joke to play on someone. My apologies for sounding like an idiot, but I just have never seen an engine produce that much air through the crankcase.
On OHC engines the cams are moving lotsa air. Oil is spraying on them. I topped off the oil in my 528e and forgot to replace the cap. 3 hrs/ 150 miles later, the low oil level light came on. The engine had slung a qt of oil out the open cap in that time.
You felt a breeze, but probably it was a pulsation - an in and out.
This would be normal and expected.
Unless the starter is broken, turn off the car next time you add oil.
I would check the PCV system to be sure, though.
This would be normal and expected.
Unless the starter is broken, turn off the car next time you add oil.
I would check the PCV system to be sure, though.
so you live and learn. No more oil fill with engine running.
It's probably designed to do this. Ask on a Scion forum for people to conduct this experiment on the same engine as yours.
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My jeep does this. If it was REALLY from a tired engine, there would be lots of smoke involved in the purging.
I'll check mine again, but my 2.5 puts out a good volume at idle (air). I'll do the paper thing (sometime take a piece of paper to your tail pipe, it should be always pushed away from it, if it gets sucked back in and flutters against the pipe, you've got valve problems) to see if it's truly an output or a in
ut cycling pulse.
I'll check mine again, but my 2.5 puts out a good volume at idle (air). I'll do the paper thing (sometime take a piece of paper to your tail pipe, it should be always pushed away from it, if it gets sucked back in and flutters against the pipe, you've got valve problems) to see if it's truly an output or a in
ut cycling pulse.
I've got a 3L 4cyl turbodiesel, and the pulsations are amazing with the cap off.
When you look at a 4 cylinder engine, with a finite length con-rod, the diplacement above (and therefore below) the pistons varies with engine rotation, giving a twice per revolution peak/minimum.
There will be around 3-5% of your swept volume trying to get out of/into the filler cap, twice per revolution.
When you look at a 4 cylinder engine, with a finite length con-rod, the diplacement above (and therefore below) the pistons varies with engine rotation, giving a twice per revolution peak/minimum.
There will be around 3-5% of your swept volume trying to get out of/into the filler cap, twice per revolution.
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